[aabir]

Hello everybody
I have been trying to generate mesh for turbulent flow around a rod with complex roughness. I plan to use the SST model and thus have very fine inflation layers near the walls of the rod. Unfortunately my meshing is taking too long (more than a day!!) and finally it showed a number of errors. Can anyone suggest what should be the correct approach for meshing complex geometries.

[diamondx]

I moved your thread to another section.
Please post picture of your mesh if you want feedback from people.
If your mesh takes one day to generate, something is clearly wrong. I would suspect a small size to the element . give a better size. some relatively bigger

[Far]

Originally Posted by aabir

Hello everybody
I have been trying to generate mesh for turbulent flow around a rod with complex roughness. I plan to use the SST model and thus have very fine inflation layers near the walls of the rod. Unfortunately my meshing is taking too long (more than a day!!) and finally it showed a number of errors. Can anyone suggest what should be the correct approach for meshing complex geometries.

You may not be able to mesh for roughness in body which is usually at much lower scale compared to geometry. For these type of analysis create simple usual mesh and use roughness features in boundary conditions and turbulence model available in solver, which will give you sort of average effect. But that should be enough for any engineering analysis.

[aabir]

Originally Posted by Far

You may not be able to mesh for roughness in body which is usually at much lower scale compared to geometry. For these type of analysis create simple usual mesh and use roughness features in boundary conditions and turbulence model available in solver, which will give you sort of average effect. But that should be enough for any engineering analysis.

Thank you for your inputs. I have attached the cross section of the flow and views of my geometry. I am using symmetry for the model. I am using SST for turbulence modeling and thus need 5-15 inflation layers within Y+=5 (so the inflation first layer thickness need to be around 2e-6 m).
The length of the rod is 1.253m (with threads encompassing .2667 m of the inner rod surface; the rest being smooth).

[aabir]

Originally Posted by diamondx

I moved your thread to another section.
Please post picture of your mesh if you want feedback from people.
If your mesh takes one day to generate, something is clearly wrong. I would suspect a small size to the element . give a better size. some relatively bigger

I have added pictures in my reply. Please let me know if it helps.
Thanks

[Far]

that looks fine to me. go ahead with simulation

[diamondx]

Looks fine.